SPM 06-28-2021: Second Debris Flow in Glenwood Canyon

Issue Date: Monday, June 28, 2021
Issue Time: 9:55 AM MDT

Summary:

Scattered thunderstorms began to form along the Front Range Mountains and Urban Corridor in the early afternoon yesterday, as well as the Northeast Plains. Storms generally moved northeastward and allowed for training cells, especially on the Northeast Plains. By late afternoon-early evening, storm coverage had also filled in in the Northern, Central, and San Juan Mountains. Rainfall rates with these storms were generally low however, resulting in low 24-hour accumulations. For rainfall estimates in your area, check out the State Precipitation Map below.

Even with lower total storm accumulations, after several days of consistent rainfall burn scars were particularly vulnerable to flood conditions. For the second time this weekend, a debris flow from rainfall on the Grizzly Peak burn scar closed I-70 in Glenwood Canyon. Rainfall over the burn area on Sunday was light, less than 0.25 inches, but still enough to produce a debris flow coverage area of 80 feet wide and 5 feet deep, as seen in the pictures tweeted from CDOT.

⚠UPDATE: I-70 Glenwood Canyon is closed overnight from Exit 87 to Exit 133. CDOT crews will continue clearing mudflow debris overnight and will reassess the debris & closure in the morning. All updates will post https://t.co/SO2TG3LpBX courtesy #GlenwoodSprings Fire Dept. https://t.co/aeyhy3S6SL pic.twitter.com/Yi3CKQTSW7

— Colorado Department of Transportation (CDOT) (@ColoradoDOT) June 28, 2021

There was also flooding on the Calwood burn scar in Jamestown yesterday. A flood advisory was issued in the evening, followed by a upgrade to flash flood warning after Doppler radar indicated heavy rain. Law enforcement in Jamestown reported a 3-4 foot surge of debris and water flowing down Geer Canyon.

Click Here For Map Overview

The map below shows radar-estimated, rainfall gage-adjusted Quantitative Precipitation Estimates (QPE) across Colorado. The map is updated daily during the operational season (May 1 – Sep 30) by 11AM. The following six layers are currently available: 24-hour, 48-hour and 72-hour total precipitation, as well as maximum 1-hour, 2-hour and 6-hour precipitation over the past 24 hour period (to estimate where flash flooding may have occurred). The 24-hour, 48-hour and 72-hour total precipitation contain bias corrections that are not disaggregated into the hourly estimates, so there will likely be some differences. The accumulation ending time is 7AM of the date shown in the bottom right corner. Also shown optionally are vulnerable fire burn areas (post 2012), which are updated throughout the season to include new, vulnerable burn areas. The home button in the top left corner resets the map to the original zoom.